brown fat

noun

One of two types of fatty tissue in mammals, especially in newborn infants and hibernating animals, that is composed of dark-colored cells containing numerous mitochondria and lipids, which are converted into body heat.

brown fat - Medical Definition

n.

One of two types of fatty tissue in mammals, especially in newborn infants and hibernating animals, that is composed of dark-colored cells containing numerous mitochondria and lipids, which are converted into body heat.